According to one aspect of the present invention, we provide a method for lining a pipe or main comprising heating a length of synthetic-resin liner pipe of external diameter substantially equal to or greater than the internal diameter of the pipe or main to be lined, mechanically deforming the heated liner pipe to reduce its external diameter to less than the internal diameter of the pipe or main to be lined, causing the liner pipe to enter the pipe or main to be lined and pressurising the internal wall of the liner pipe to cause it to expand into engagement with the internal wall of the pipe or main to be lined.
According to another aspect of the present invention, a closure is provided for closing off the end of a synthetic resin liner pipe during internal pressurisation of the pipe with a pressurising fluid, the closure comprising a cap having a sleeve portion adapted to receive the end of the pipe with clearance and flexible sealing means located within the sleeve and adapted to engage the outer surface of the pipe and form a seal between the outer surface of the pipe and the inner surface of the sleeve portion.